[USA] A diverse mix of species improves the stability and fuel-oil yield of algal biofuel systems, as well as their resistance to invasion by outsiders, according to the findings of a federally funded outdoor study by University of Michigan researchers.

U-M scientists grew various combinations of freshwater algal species in 80 artificial ponds at U-M’s E.S. George Reserve near Pinckney in the first large-scale, controlled experiment to test the widely held idea that biodiversity can improve the performance of algal biofuel systems in the field.

Overall, the researchers found that diverse mixes of algal species, known as polycultures, performed more key functions at higher levels than any single species—they were better at multitasking. But surprisingly, the researchers also found that polycultures did not produce more algal mass, known as biomass, than the most productive single species, or monoculture.

“The results are key for the design of sustainable biofuel systems because they show that while a monoculture may be the optimal choice for maximizing short-term algae production, polycultures offer a more stable crop over longer periods of time,” said study lead author Casey Godwin, a postdoctoral research fellow at U-M’s School for Environment and Sustainability.

The team’s findings are scheduled for publication June 18 in the journal Global Change Biology-Bioenergy.

Algae-derived biocrude oil is being studied as a potential renewable-energy alternative to fossil fuels. Because they grow quickly and can be converted to bio-oil, algae have the potential to generate more fuel from less surface area than crops like corn. But the technical challenges involved in growing vast amounts of these microscopic aquatic plants in large outdoor culture ponds have slowed progress toward commercial-scale cultivation.

Outside—far from the controlled conditions of the laboratory—an algal biofuel cultivation system must maintain steady, stable growth of fuel-ready algae in the face of fluctuating weather conditions, the threat of population crashes caused by diseases and pests, and invasion by nuisance species of algae.

Decades of ecological research have demonstrated that plant and animal communities containing a rich mix of species are, on average, more productive than less-diverse communities, more stable in the face of environmental fluctuations, and more resistant to pests and diseases.

Photo: Samples collected from large tanks containing mixes of various freshwater algal species. The green samples are healthy, while the yellow samples were contaminated by a fungal disease. The biofuels experiment was conducted in the summer of 2016 at U-M’s E.S. George Reserve near Pinckney, Mich Credit: Daryl Marshke/Michigan Photograp

A special priority would be given to any locations that are subject to a "state of emergency" designation within the previous 12 months because of blooms. In Florida, 13 counties affected by algal blooms this summer fall under that designation.

Chelsea Briganti and Leigh Ann Tucker, co-founders of LOLIWARE, "the world's first edible bioplastics company" are changing the way we think of eco-friendly straw use. LOLISTRAW is a "hypercompostable" and marine-degradable straw. Oh yeah, and you can eat it.